In the equipment of semiconductor manufacture, it is a conventional practice to place its heater under control of the controller depending upon a temperature-change pattern of a preset target temperature because of the necessity of maintaining the furnace interior proper in temperature or causing the furnace interior to follow the designated change of temperature (see Patent Document 1, for example).
Patent Document 1: JP-A-2000-18307 (pages 11-21, FIG. 1)